In people without diabetes, the "after meal" blood sugar level is very carefully controlled. Insulin (the hormone that lowers blood sugar) and glucagon (hormone that raises blood sugar) play a key role in keeping this careful balance. We now know that a substance made by the body called GLP-1 also helps with this careful balance. GLP-1 works in four ways. First, it helps to stimulate the cells in the pancreas to produce more insulin. Secondly, it helps to "dampen" the glucagon response (glucagon is released after a meal and causes the blood sugar to rise). Thirdly, GLP-1 delays the digestion of food in the stomach. Lastly, it seems to "dampen" the appetite, which causes a person to eat less.